import java.util.HashMap;
import java.util.HashSet;

public class Main {

    public static void main(String[] args) {
        int a = 42;
        System.out.println(Integer.valueOf(a).hashCode());

        int b = -42;
        System.out.println(Integer.valueOf(b).hashCode());

        double c = 3.1415926;
        System.out.println(Double.valueOf(c).hashCode());

        String d = "imooc";
        System.out.println(d.hashCode());

        Student student = new Student(3, 2, "ssss", "zhang");
        System.out.println(student.hashCode());

        HashSet<Student> hashSet = new HashSet<>();
        hashSet.add(student);

        HashMap<Student, Integer> scores = new HashMap<>();
        scores.put(student, 100);
    }

}
